As the continuing advances in technology have enabled the further miniaturization of the components required to build computer systems, new categories of computer systems have been created. One of the newer categories of computer systems developed has been the portable, hand held, or “palmtop” computer system, referred to as a personal digital assistant or PDA. Other examples of a palmtop computer system include electronic address books, electronic day planners, electronic schedulers and the like.
A palmtop computer system is a computer that is small enough to be held in the user's hand and as such is “palm-sized.” As a result, a palmtop is readily carried about in the user's briefcase, purse, and in some instances, in the user's pocket. By virtue of its size, the palmtop computer, being inherently lightweight, is therefore exceptionally portable and convenient.
Continuing miniaturization has provided for the development of additional functionality, which can be incorporated into some portable computer systems. One such additional functionality incorporated into some portable computer systems has been wireless (radio) capability. Some portable computer systems are equipped with radio transceivers (receiver/transmitter) that provide two way communication between a wireless communications network and the portable computer system. Further, in addition to the main processor, the portable computer system may also include a DSP (digital signal processor), adapted for processing of data to be transceived. The DSP performs some of the communication processes that would have been performed by the main processor.
Generally, most portable computer systems are powered by disposable or rechargeable batteries. Because the reduced size of the portable computer system, such that it is deemed “palm-sized,” predicates the volume of energy which may be stored within, smaller batteries are being utilized to comply with the diminutive size of the portable computer system. Further, the portable computer system's power consumption is a significant consideration in reducing the rate with which the batteries either need to be replaced or recharged. Accordingly, portable computer systems are enabled to be placed into a minimum or low power mode, such as a sleep mode or a deep sleep mode, while the system is not processing a specific function or particular operation.
Until recently, when communication occurred between the portable computer system and a wireless network, the portable computer system was aware of an expected transmission of data. For example, when data was being wirelessly transceived by the portable computer system, is was in response to a request by the portable computer system. Accordingly, the portable computer system was purposefully placed into a transceiving state when a transmission was anticipated or desired, but otherwise was not in a transceiving mode.
Because of the ever increasing complexity within the portable computer system, the portable computer system is frequently being implemented in applications that require continuous transceiving readiness, much like a cellular telephone. For example, when a cellular telephone is powered up, it is enabled to receive calls at any time. By the same token, a portable computer system is able to receive, or transmit, data or information nearly any time the transceiver is powered up, regardless of whether other components are in a sleep (low power consumption) mode.
It is desirable for the portable computer system (with a wireless transceiver) to remain “in coverage” when the transceiver is powered up, such that uninterrupted wireless communication is enabled. However, due to, in part, its portability, there may be instances when the signal strength may fluctuate such that the communicative link between the portable computer system and the wireless network is lost. Additionally, dependent upon the amount of signal strength fluctuation, the portable computer system may entirely lose the communication link, so as to be considered “out of coverage.” For example, the portable computer system has, while in one location, an established connection utilizing a particular broadcast channel of a network. Subsequent to or during relocation, the signal strength of that channel may fluctuate such that the communication signal may be lost.
Currently, during signal strength monitoring, the radio components are powered up for checking and then powered down afterward, or the radio components are powered up continuously, which has an adverse affect on the power supply of the portable computer system. Additionally, the main processor is commonly activated during this monitoring, which is also a substantial drain on the portable computer system's power supply.